Questions tagged [cochran-q]

Cochran's Q test is a nonparametric analog to the repeated measures ANOVA when the outcome is dichotomous/binary.

Cochran's Q is an omnibus test for stochastic dominance in $b$ blocks (e.g. individuals) across $k$ groups with nominal outcome data (specifically outcomes coded 0/1); it effectively generalizes McNemar's test to two or more groups. The null hypothesis is that the probability of success in each of $k$ groups is the same.

Post hoc pairwise comparisons may be carried out using either Cochran's Q test for each pair, or with McNemar's test. Adjustments for multiple comparisons, using either family-wise error rate, or false discovery rate methods are then appropriate.

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Effect size of Cochran's Q

I have performed a Cochran's Q test for a within-subjects experimental design with 3 conditions and 36 participants with a dichotomous dependent variable. I found a (just) statistically significant effect ($\chi^2$ = 6.00, df = 2, p = 0.04979) and…
Ham
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Q-Test of Heterogeneity for only two effect sizes?

I am using the Q-Test of Heterogeneity to investigate if several effect sizes derived from two different studies are significantly different from each other. More precisely, I have, for every effect of interest, a Cohen's d from one study, and one…
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Calculating heterogeneity (Cochrane $Q$ and $I^2$ statistics) in random effects model

I want to ask whether I can calculate the Cochrane $Q$ and $I^2$ statistics in a random effect model. I collected some data from different areas and want to compare the prevalence of allergic sensitization on different areas. However, the Cochrane…
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Analyze Repeated Measures of a Frequency

I have the same group of participants (n=31,000) that answered the following question "What is your favorite subject?" by selecting one of three answer options (Science, Math, Art) at two different timepoints (Year 1 and Year 2). In the data table,…
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Meta-analysis: How to interpret a non-significant Q statistic but high I squared

I'm reviewing some meta-analyses on psychotherapies and trying to make sense of the statistics related to heterogeneity, specifically Cochran's Q and the I-squared value. I'm confused about how to interpret a non-significant Q statistics while the…
Strooby
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Are there good alternatives to Cochran's Q test for heterogeneity in meta-analysis?

We used the Q test to determine heterogeneity with p-values <0.10. A highly recognised statistician commented that the Q test has low power and that it should not be used to determine presence of heterogeneity. My questions: Low power is a known…
antonio
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Is it worth doing (single-armed) meta analysis if the studies' heterogeneity is very large?

I'm currently trying to perform a single-armed meta analysis of immunotherapy on breast cancer, which I believe this meta analysis will be the first among its intervention and cancer subtype. The problem is, when I test the heterogeneity using…
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Can Cochran's Q test take a 3 level nominal variable as the response (instead of 2)?

I conducted a study using within-subjects (repeated measure) design for collecting nominal data. I have been reading a lot closet I get for a suitable test is Cochran's Q test since I have repeated measures for nominal data from the 3…
Fatma S
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Test for homogeneity in meta-analysis with a large number of studies

So I am conducting some literature searches on behalf of someone. I stumbled across a meta-analysis which used 23 studies. It tested the homogeneity of the studies used, using what I think is a Cochran's Q test. The output is as…
googleplex101
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Cochran's Q & McNemar tests together

I have binomial outcome data for three groups that I am analyzing with Cochran's Q test. As discussed at this site, Cochran. However, I have to repeat this seven different times because I am analyzing performance of three diagnostic tests to see…
user918967
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Appropriate homogeneity test for meta-analysis

I'm looking at measures from different studies (for a meta-analysis) and hoping to provide an aggregate effect size. I'm trying to identify hetero-/homo-geneity to determine whether I should use a random or fixed effects model. I do not have the…
d-cubed
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Alternatives to Chi-square test when observations are dependent

I have cross-tabulated some data from a survey. The core survey questions have been cross-tabulated with demographic variables. I am looking at these cross-tabulations to see if any interesting trends occur. So the process i am going through is…
GaryStats
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How does tau squared (between-study variance) differ for network meta-analysis versus pairwise meta-analysis?

I'm currently trying to replicate a random effects network meta-analysis in Excel. When estimating between-study heterogeneity, I can calculate Cochran's Q just fine via: $$Q=\sum w_i(y_i-\hat\theta)^2$$ However, I run into issues when trying to…
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is mcnemar's test suitable to evaluate the differences of the proportions of events between the subgroups of risk scores?

the authors indicated that comparing event frequencies of events between subgroups( example frs and df) of groups ( low intermediate high) mcnemar's test was used. is it right for this study design?
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calculate the change in standard deviation for metaanalysis

I am trying to calculate the change in standard deviation for my metaanalysis. I have the following data available: mean for control group at baseline and endpoint mean for intervention group at baseline and endpoint 95% Confidence interval for…
anu
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